It is currently impossible to easily find music (Albums & Tracks) that you save for offline access in the new iOS app. An Offline tab is required with full sorting capability.
The same method / implemetation used for offline playlists was used for My Music. It never worked well for Playlists, and definitely Does Not work for My Music.
And while you're at it, please include the ability to free up device storage when deleting offline music.
Thanks for your idea @philmg Currently this idea is implemented as you can now filter by 'Downloads' to see only your synced content on the mobile apps.